Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false), so the bar is lower, yet the description adds real operational context: it is a live snapshot, employees without an open shift are excluded, and it requires a Cotlet API key with app access. Only the return format's edge behavior (e.g., pagination or empty result) is unaddressed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The first sentence front-loads the purpose well, but the payload fields ('job, task and the GPS location of their last punch') are restated almost verbatim in the third sentence. That duplication costs efficiency without adding information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an empty input schema and no output schema, the description carries the burden of explaining the response, and it does name the returned fields, the exclusion rule and the auth prerequisite. It is close to complete, missing only what an empty or multi-employee result looks like.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is nothing the schema or description needs to disambiguate; the baseline for a parameterless tool is 4.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource ('Employees on an active shift now') and pins the scope to a real-time snapshot, which cleanly separates it from siblings like clockshark_list_time_entries and clockshark_list_shifts. An agent knows immediately this is a 'who is currently clocked in' query.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied through the scope statement ('Returns employees with an open shift at the moment of the call'), but there is no explicit when-to-use guidance or named alternative for historical time data. The agent must infer that clockshark_list_time_entries is the different tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.